As the New Republic era picks up and starts to culmiante with a major conflict involving the Grand iral Thrawn and the Imperial Remnant, it makes sense for Luke Skywalker to make future appearances involving more action with extended roles compared to what's been seen via CGI de-aging. With that in mind, I think I'd rather see Luke being recast with Sebastian Stan, something Mark Hamill wants to see happen (and the two actors have allegedly talked about it). I think this would be better than the CGI/finding some contrived excuse to explain Luke's absence.